Tag: MCQ

Question

HLA complex in man is located on DNA structure (photograph) numbered ?

A. 2.

B. 4.

C. 6.

D. 8.

Show Answer

Correct Answer » C

Explanation

Ans:C. 6

HLA complex in man is located on chromosome 6.

Human leukocyte antigen (HLA) complex

It is a gene complex encoding the major histocompatibility complex (MHC) proteins in humans.

These cell-surface proteins are responsible for the regulation of the immune system in humans.

The HLA gene complex resides on a within chromosome 6.

HLAs corresponding to MHC class I (A, B, and C) present peptides from inside the cell. For example, if the cell is infected by a virus, the HLA system brings fragments of the virus to the surface of the cell so that the cell can be destroyed by the immune system.

Question

A 25 year old woman suffered from weakness in the eye muscles (as shown in the image) which later progressed to weakness in the proximal limb muscles.Weakness is typically least severe in the morning and worsens as the day progresses.
and it gets increased by exertion and alleviated by rest.The auto-immune condition which the patient is suffering from is a which type of hypersensitivity reaction ?

A. Type 1.

B. Type 2.

C. Type 3.

D. Type 4.

Show Answer

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Correct Answer » B

Explanation

Ans:B. Type 2

The patient in question is suffering from Myasthenia Gravis

Myasthenia gravis (MG) is a rare autoimmune disorder of neuromuscular transmission in which antibodies form against acetylcholine nicotinic postsynaptic receptors at the neuromuscular junction of skeletal muscles.

Hypersensitivity reaction

Hypersensitivity is a set of undesirable reactions produced by the normal immune system, including allergies and autoimmunity.

Question

The cells marked by a “black arrow” in the blood smear of a patient given below are most commonly seen in cases of ?

A. Sickle Cell Anemia.

B. Thalassemia.

C. Myeloproliferative disorders.

D. Both A & C.

Show Answer

Correct Answer » D

Explanation

The cells marked by a black arrow in the blood smear of a patient given above representsTear-Drop Cells.

Ans: D. Sickle Cell Anemia,Thalassemia,Myeloproliferative disorders.

Tear Drop Cell

A deformedRBCwhich is tugged to a nipple at oneend,havingsqueezedthrough a reticuloendothelialsystemwith increasedconnectivetissue.

It is found in conditions as follows:

Myelofibrosis,andotherreticuloendothelialreplacementdisordersthatcompromisethebonemarrowspace,causingsplenicoverload or decreasedfunctionalsplenictissue e.g.,megaloblasticanaemia,hereditaryelliptocytosis,anaemia of renaldisease,haemolyticanaemias,sicklecellanaemia,thalassemia,andbonemarrowinfiltration by haematologicandnon-haematologicmalignancies.

Question

Identify the hematological disorder shown in the photograph below ?

A. lron deficiency anemia.

B. Megaloblastic anemia.

C. Thalassemia.

D. Lead poisoning.

Show Answer

Correct Answer » A

Explanation

Iron deficiency anemia develops when body stores of iron drop too low to support normal red blood cell (RBC) production. Inadequate dietary iron, impaired iron absorption, bleeding, or loss of body iron in the urine may be the cause.Iron equilibrium in the body normally is regulated carefully to ensure that sufficient iron is absorbed in order to compensate for body losses of iron.

CBC results in iron deficiency anemia include the following:

Low mean corpuscular volume (MCV)

Low mean corpuscular hemoglobin concentration (MCHC)

Elevated platelet count (>450,000/µL) in many cases

Normal or elevated white blood cell count

Peripheral smear results in iron deficiency anemia are as follows:

RBCs are microcytic and hypochromic in chronic cases

Platelets usually are increased

In contrast to thalassemia, target cells are usually not present, and anisocytosis and poikilocytosis are not marked

In contrast to hemoglobin C disorders, intraerythrocytic crystals are not seen.

Inheritance patterns for single gene disorders are classified based on whether they are autosomal or X-linked and whether they have a dominant or recessive pattern of inheritance. These disorders are called Mendelian disorders.

Autosomal Dominant Inheritance

Only one copy of a disease allele is necessary for an individual to be susceptible to expressing the phenotype.

With each pregnancy, there is a one in two (50%) chance the offspring will inherit the disease allele.

Unless a new mutation has occurred, all affected individuals will have at least one parent who carries the disease allele.

Autosomal dominant inheritance is often called vertical inheritance because of the transmission from parent to offspring.

Across a population, the proportion of affected males should be equal to the proportion of affected females.

In autosomal recessive inheritance, two copies of a disease allele are required for an individual to be susceptible to expressing the phenotype.

Typically, the parents of an affected individual are not affected but are gene carriers.

With each pregnancy of carrier parents:

There is a one in four (25%) chance the offspring will inherit two copies of the disease allele and will therefore have the phenotype.

There is a one in two (50%) chance the offspring will inherit one copy of the disease allele and will be a carrier.

There is a one in four (25%) chance the offspring will inherit no copies of the disease allele and will not express the phenotype or be a carrier. This individual would not be at risk for passing the disorder on to his/her offspring.

As with autosomal dominant inheritance, the proportion of affected males should be equal to the proportion of affected females in a given population.

As in autosomal dominant inheritance, only one copy of a disease allele on the X chromosome is required for an individual to be susceptible to an X-linked dominant disease.

Both males and females can be affected, although males may be more severely affected because they only carry one copy of genes found on the X chromosome.

When a female is affected, each pregnancy will have a one in two (50%) chance for the offspring to inherit the disease allele. When a male is affected, all his daughters will be affected, but none of his sons will be affected.

Question

The histopathological picture of a patient suffering from carcinoma is shown below.The multiple,round figures seen in the image is due to a mineral deposition .It can be seen in all of the following conditions,except:

A. Papillary thyroid carcinoma

B. Adenocarcinoma of Lung

C. Meningioma

D. Squamous cell carcinoma of Tongue.

Show Answer

Correct Answer » D

Explanation

Ans:D. Squamous cell carcinoma of Tongue.

The histopathological picture shows Psammoma Bodies.

Psammoma bodies

They are round microscopic calcific collections.

It is a form of dystrophic calcification.

Necrotic cells forms the focus for surrounding calcific deposition.

They have a lammelated concentric calcified structure, sometimes large enough to be seen on CT.

Psammoma bodies are found in a diverse group of tumours which include: